Thus, for planets found in gaps (i.e. when the surface density of the circumstellar disc is negligible), it may not be necessary to correct for any extinction at H \(\alpha \)  within the system.
It also suggests that the paucity of detected planets might not be mainly due to heavy extinction by the accreting material but rather to a less efficient conversion of the accretion energy to H \(\alpha \)  than for CTTSs [1]}.
